By ABE ABORAYA, SPECIAL TO SEATTLEPI.COM

Published 10:00 pm, Thursday, July 1, 2010

A view of Chester Morse Lake in the Cedar River Watershed, where Seattle gets much of its drinking water. | View photo gallery

At home, 36-year-old Yukiko Sodos drinks water straight from the tap. Her sister, Miki Sodos, 34, filters the water in a pitcher before she'll take a drink.

The pair, both owners of Bang Bang Café in Belltown, are, perhaps, more knowledgeable than many about water. Their mother quit drinking tap water when she was diagnosed with cancer, and they came to Seattle from Albuquerque, N.M. -- a city with notoriously unsafe levels of arsenic in the water.

"I think the water quality is pretty good here," Yukiko said. "I think they can work on it more though, to ensure that people don't have to buy bottled water."

Seattle has some of the cleanest water in the country. The 2010 Annual Drinking Water Quality Report, a report mandated by the Environmental Protection Agency, tested the water along 10 parameters for health risks.

They were looking for heavy metal contaminants, like lead and copper; microbial nasties that can get the population sick and potentially cause deaths to the young, elderly and immune-system compromised; and byproducts from cleaning the water. Not one single measure was above the levels established by the EPA.

What's more, when The Associated Press started running an annual investigation into trace amounts of pharmaceuticals in the water, Seattle has consistently come clean. There aren't any pharmaceuticals in the water either.

When drinking water is contaminated, it can be deadly.

In 1993, during a two-week outbreak of Cryptosporidium in the Milwaukee area, more than 400,000 people became sick with cramps, fever, diarrhea and dehydration. More than 69 people died, according to one study. The outbreak cost $96.2 million -- $31.7 million in medical costs and $64.6 million in productivity losses.

So how does Seattle keep its water clean? When the Sodos sisters turn on their tap and get clean water, where does it come from? The answer starts more than 35 miles away at the Cedar River Watershed and the Tolt River Watershed, where an unspoiled wilderness sits in the Cascade Mountains.

The city owns almost 91,000 acres of land around the Cedar River Watershed, more than 99.6 percent of the hydrographic boundary that feeds the river. By owning the land, the city protects the source of the water. That's nearly twice the 50,000 acres of the city itself. The same's true for the Tolt.

So why did the city invest millions of dollars over the course of a century to protect the water supply? Like so much of Seattle's history, it all began with the Great Seattle Fire of 1889.

The history

On June 6, 1889, John E. Back accidentally started the Great Seattle Fire heating glue over a gasoline fire, burning down Seattle's burgeoning business district. Firefighters had access to water from Lake Washington to fight the blaze, but they didn't have enough water pressure to suppress the blaze. And so Seattle burned.

One month later, the citizens of Seattle voted to get their water from the Cedar River instead, piping it in from Landsburg. At the time, the highest hill in Seattle was Queen Anne Hill at 524 feet; Landsburg was 550 feet.

That meant they could use gravity to pressurize pipes from Landsburg to a water tower on Queen Anne Hill, and then pressurize the rest of the city. The system came online in 1901.

In 1906, a railroad company wanted to put a rail line directly through the watershed, and Seattle's mayor and city commission vehemently fought the development. They were worried about human waste from the trains getting into the water, as well as fires and the potential for a spill.

They lost the battle and the rail went in. But in the long run, that loss won the war. It started a revolution in thinking about water.

From here on out, Seattle decided that to truly protect its water source, it had to own all the land around the watershed.

"An ounce of prevention is worth a pound of cure," said Ralph Naess, public education specialist for Seattle Public Utilities. "And that's really the fundamental concept that the founding fathers of Seattle came up with."

Naess spins the yarn of why Seattle owns the watershed in front huge model display of the watershed. Soon, he'll start a tour of the watershed, where pristine landscape is kept hidden away from a potentially polluting public -- the only way in is with a supervised tour.

"For most of us, water's like air," Naess said. "We're lucky. We don't think about it. We just expect that it'll be there, 24-7, 365, when we turn on the faucet. ... That is an extremely complex process to make that happen. And it all starts here."

The majority of the water Seattle drinks -- 70 percent -- comes from the Cedar River Watershed; the remaining 30 percent comes from the Tolt River Watershed. (A tiny fraction comes from wells used as a backup.)

Rain and snow land on the top of the Cascades and flow downhill, where the land acts as a natural filter. Then the water is treated at either the Tolt Reservoir or Lake Youngs. The water is hit with chlorine to kill bacteria, and with ultra-violet light and ozone to cleanse even deeper. Then it's hit with chlorine a second time.

And then it's piped to you.

Constant vigilance

SPU constantly monitors the water for anything and everything that can make the populace sick.

Wylie Harper, the director of a small lab on Stacy Street, oversees a team of 25 scientists and support staff.

There's a map tacked to a wall in a conference room. It shows all of the city of Seattle, all the surrounding municipalities the city sells water to and even the watershed.

On the map are more than 200 blue dots. They represent the sampling stations where water is collected and brought back to the lab for testing.

The idea is simple: They want to keep a running tab on the water, both spatially -- testing all the water in the system -- and temporally. Each of the 200 dots is sampled, on average, at least once a week.

The water comes back to the lab in plastic bottles. Then the chemists, microbiologists and luminologists do their work (a luminologist is to fresh water what a microbiologist is to salt water).

So what are they looking for? The short answer is, everything that's in that water quality drinking report. But microbials like Giardia, Cryptosporidium and E. coli are the ones they're most concerned with.

"From a health perspective, that's true," Harper said. "Because if you have something bad microbially, it's a quick turnaround issue. You need to be on top of it."

Harper opens an industrial refrigerator and pulls out a bottle a shade bigger than a salt shaker, one of many from inside. The clear bottle looks like a urine sample.

The substance turning the water yellow is food for bacteria, to allow the little guys to grow and multiply if they're already in the water. In 24 hours, any E. coli in the water will turn it from yellow to magenta, meaning there's one of the many strains of E. coli present, most of which are harmless.

But if it fluoresces under a UV light, then it's a fecal E. coli, and more likely to be dangerous. They do occasionally find the bug in the water.

"The good news there is it's not very robust in terms of a contaminant," Harper said. "It hits the treatment process, chlorine takes care of it easily. You hit it with ozone and UV, there's just nothing left. We're more concerned about it downstream, if we have a pipe break or leak where contamination can occur."

In recent memory, SPU has only had one "boil water" notice. And that, Harper said, was a conservative response to a broken main.

They also test the water for heavy metals, like lead and copper, that can be leached from the plumbing in a home, as well as other metals the water can naturally pick up. They also make sure the residual disinfectant levels aren't too high -- they can be dangerous as well, but they also affect the taste.

Derrick Dennis, the water quality supervisor in the Department of Health's Office of Drinking Water, said Seattle goes beyond the minimum requirements.

"I would say the water quality is good, and I would also credit it to the dedication of the people running the system," he said.